fix CPPLINT in sorting folder

(cherry picked from commit 7efa52e067)

sorting/numeric_string_sort.cpp

@@ -0,0 +1,54 @@
+// Using general algorithms to sort a collection of strings results in
+// alphanumeric sort. If it is a numeric string, it leads to unnatural sorting
+
+// eg, an array of strings 1,10,100,2,20,200,3,30,300
+// would be sorted in that same order by using conventional sorting,
+// even though we know the correct sorting order is 1,2,3,10,20,30,100,200,300
+
+// This Programme uses a comparator to sort the array in Numerical order instead
+// of Alphanumeric order
+
+#include <algorithm>
+#include <iostream>
+#include <string>
+#include <vector>
+
+bool NumericSort(std::string a, std::string b) {
+    while (a[0] == '0') {
+        a.erase(a.begin());
+    }
+    while (b[0] == '0') {
+        b.erase(b.begin());
+    }
+    int n = a.length();
+    int m = b.length();
+    if (n == m) return a < b;
+    return n < m;
+}
+
+int main() {
+    int n;
+    std::cout << "Enter number of elements to be sorted Numerically\n";
+    std::cin >> n;
+
+    std::vector<std::string> v(n);
+    std::cout << "Enter the string of Numbers\n";
+    for (int i = 0; i < n; i++) {
+        std::cin >> v[i];
+    }
+
+    sort(v.begin(), v.end());
+    std::cout << "Elements sorted normally \n";
+    for (int i = 0; i < n; i++) {
+        std::cout << v[i] << " ";
+    }
+    std::cout << "\n";
+
+    std::sort(v.begin(), v.end(), NumericSort);
+    std::cout << "Elements sorted Numerically \n";
+    for (int i = 0; i < n; i++) {
+        std::cout << v[i] << " ";
+    }
+
+    return 0;
+}